I bought Water Wisteria a few weeks ago and it keeps dropping leaves and the stems are turning brown. Is there a possibility there's not enough light? I thought Wisteria was a pretty sturdy plant, thriving in either high light or low light. Anyone have any ideas?

I have a super bright LED desk lamp that is great for all my other plants (My fanwort started growing roots after I started using this light). But I have a bigger tank now (10 gal. used to have a 5 gal.) so maybe I need to get a second lamp?
The Wisteria is growing a lot of roots, but it's dropping a lot of leaves and some of the stalks are turning brown.